Homebrew PCBs

>From: "Dave Mucha" <dave_mucha@...>
>Reply-To: Homebrew_PCBs@yahoogroups.com
>To: Homebrew_PCBs@yahoogroups.com
>Subject: [Homebrew_PCBs] board isolation cut-outs
>Date: Thu, 30 Sep 2004 04:06:40 -0000
>
>Hi all,
>
>I'm looking to measure a 300 volt line and drop it to 5 volts.   One
>of the many problems is that there is also the potential of a 15kV
>spike on the line.
>
>I would appreciate any help finding parts that can withstand the high
>voltage.   And any links to information on what to watch out for.
>
>
>But, for this group.  Does anyone have any ideas on how to determine
>the slices in a PCB around chips ?   I would like to isolate the 15kV
>pulse from the rest of the board.   A second board is a very good
>possibility.
>

A transient suppressor will deal with spikes. 5V ones are available - try 
Googling for 'TransGuards'.

Leon